In semiconductor manufacturing apparatuses, transfer apparatuses are employed in order to transfer the semiconductor wafers between the processing apparatuses. Standard transfer apparatuses of this type are transfer apparatuses in which the semiconductor wafer cassette jig is loaded on a transfer carriage, and transfer apparatuses in which the semiconductor wafers are transferred one at a time by a robot arm. However, in such transfer apparatuses, the atmosphere of the space in which the semiconductor wafers are processed is not separated from the outside atmosphere, and the atmosphere of this space is not sufficiently clean. Recently, methods have been employed in which the semiconductor wafer cassette jig is placed in a sealed container for transfer; however, the problems of contamination from the container materials and the air tight gaskets and the like has not been solved.
For this reason, air stream transfer apparatuses which transfer semiconductor wafers through a transfer passage by means of an air stream (air bearing) have been experimentally produced, and such air stream transfer apparatuses enable a closed type (closed system) transfer passage, so that it is possible to attain a sufficiently high level of cleanliness in the atmosphere.
However, in the air stream transfer apparatuses, even if the structure is such as to contain no parts which give rise to contamination within the apparatus, so that a clean space may be maintained, there may be cases in which particles which have been brought in from the outside, for example, particles which have been deposited on the semiconductor wafers, are released within the apparatus.
Such particles present a problem in that they are then deposited on other clean semiconductor wafers. Additionally, in concert with the miniaturization and increase in functionality of the semiconductor integrated circuits and the like which are formed on these semiconductor wafers, the situation is such that, increasingly, almost no contamination or deposition of matter can be tolerated, so that this problem is important in view of an increase in the reliability of the semiconductor manufacturing apparatus and in the productivity (yield) of the semiconductor wafers.
The present invention was created in order to solve the problems described above; it has as an object thereof to provide a particle removing apparatus which is capable of preventing the deposition of particles on objects to be processed within a transfer passage.